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Nutritional requirements for protein synthesis during parasitic development of the entomophilic nematode Mermis nigrescens

Published online by Cambridge University Press:  06 April 2009

Roger Gordon  and
John M. Webster
Roger Gordon
Affiliation:
Pestology Centre, Department of Biological Sciences, Simon Fraser University, Burnaby, Vancouver, B.C., Canada
John M. Webster
Affiliation:
Pestology Centre, Department of Biological Sciences, Simon Fraser University, Burnaby, Vancouver, B.C., Canada
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Extract

Adult desert locusts were experimentally infected with a dose of 50 M. nigrescens ova and larval nematodes removed 14, 17, 21 and 24 days afterwards for in vitro radiotracer studies. These nematodes were incubated under controlled conditions either in a nutrient medium or in insect saline, which contained the appropriate 14C or 3H-labelled radioisotope. The rate of incorporation of the radioisotope into the proteins of the nematode was measured.

The rate of incorporation of 14C-leucine into proteins was greatest for the 17- day-old larvae and this accorded with the in vivo growth pattern of the nematode. This isotope was incorporated less rapidly into proteins by the 14-, 21 and 24-day- old larvae, which synthesized proteins at approximately the same rates as each other. A non-linear rate of incorporation was manifest for each of the larval stages.

Total dry weight and protein determinations showed that the nematode synthesizes relatively large quantities of non-proteinaceous reserves during the third week of infection, whilst proteins are preferentially synthesized between the 21st and 24th days of infection.

The 17-day-old nematode larvae were able to incorporate six 14C-amino acids into proteins to varying degrees. Leucine was incorporated most effectively into nematode proteins, whilst glutamic acid was the least incorporated of the six amino acids.

These nematode larvae could not effectively metabolize the 3H-dipeptide histidyl-leucine and incorporate its component amino acid residues into proteins. Similarly, a preparation of 3H-haemolymph proteins were not significantly metabolised and incorporated into proteins by the nematode. However, the nematode metabolized and incorporated an exogenous source of 14C-glucose into proteins at relatively high levels.

Incorporation of 14C-luecine into proteins was seven times more rapid for nematodes incubated in buffered insect saline than for those incubated in a more complete nutrient medium.

The dietary requirements of the nematode for protein synthesis were discussed in relation to their associated effects upon the host metabolism and an active transport of dietary amino acids into the nematode was postulated.

We wish to thank Dr H. L. Speer and Dr K. K. Nair for their helpful suggestions regarding radioisotope techniques. Thanks are also due to the National Research Council of Canada for providing financial assistance (Grant No. A4679).

Type
Research Article
Information
Parasitology , Volume 64 , Issue 1 , February 1972 , pp. 161 - 172
Copyright
Copyright © Cambridge University Press 1972

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References

REFERENCES

Baylis, H. A. (1944). Observations on the nematode Mermis nigrescens and related species. Parasitology 36, 122–32.CrossRefGoogle Scholar
Benassi, C. A., Colombo, G. & Allegri, G. (1961). Free amino acids of the haemolymph of Schistocerca gregaria Forsk. Biochemical Journal 80, 332–6.CrossRefGoogle ScholarPubMed
Beucher, E. J., Hansen, E. L. & Yarwood, E. (1971). Cultivation of Caenorhabditis briggsae and Turbatrix aceti with defined proteins. Journal of Nematology 3, 89–90.Google Scholar
Bray, G. A. (1960). A simple efficient liquid scintillator for counting aqueous solutions in a liquid scintillation counter. Analytical Biochemistry 1, 279–85.CrossRefGoogle Scholar
Gordon, R. & Webster, J. M. (1971). Mermis nigrescens: Physiological relationship with its host, the adult desert locust Schistocerca gregaria. Experimental Parasitology 29, 66–79.CrossRefGoogle ScholarPubMed
Gordon, R., Webster, J. M. & Mead, D. E. (1971). Some effects of the nematode Mermis nigrescens upon carbohydrate metabolism in the fat body of its host, the adult desert locust Schistocerca gregaria. Canadian Journal of Zoology 49, 431–4.CrossRefGoogle Scholar
Hankes, L. V. & Stoner, R. D. (1956). In vitro metabolism of dl-alanine-2C-14 and Glycine-2-C14 by Trichinella spiralis larvae. Proceedings of the Society for Experimental Biology and Medicine 91, 443–6.CrossRefGoogle Scholar
Hansen, E. L., Buecher, E. J. & Yarwood, E. A. (1964). Development and maturation of Caenorhabditis briggsae in response to growth factor. Nematologica 10, 623–30.CrossRefGoogle Scholar
Haynes, W. D. G. (1970). Taenia crassiceps: Uptake of basic and aromatic amino acids and imino acids by larvae. Experimental Parasitology 27, 256–64.CrossRefGoogle ScholarPubMed
Hill, L. (1965). The incorporation of C14-glycine into the proteins of the fat body of the desert locust during ovarian development. Journal of Insect Physiology 11, 1605–15.CrossRefGoogle Scholar
Jackson, G. J. (1962). The parasitic nematode, Neoaplectana glaseri, in axenic culture. II. Initial results with defined media. Experimental Parasitology 12, 25–32.CrossRefGoogle ScholarPubMed
Jackson, G. J. (1969). Nutritional control of nematode development. In Germ-Free Biology, pp. 331–41. Plenum Press.Google Scholar
Jaffe, J. J. & Doremus, H. M. (1970). Metabolic patterns of Dirofilaria immitis microfilariae in vitro. Journal of Parasitology 56, 254–60.CrossRefGoogle ScholarPubMed
Kulkarni, A. P. & Mehrotra, K. N. (1970). Amino acid nitrogen and proteins in the haemolymph of adult desert locusts, Schistocerca gregaria. Journal of Insect Physiology 16, 2181–99.CrossRefGoogle ScholarPubMed
Lee, D. L. (1965). The Physiology of Nematodes, 154 pp. University Reviews in Biology. London: Oliver and Boyd.Google Scholar
Levine, H. S. & Silverman, P. H. (1969). Cultivation of Ascaris suum larvae in supplemented and unsupplemented chemically defined media. Journal of Parasitology 55, 17–21.CrossRefGoogle ScholarPubMed
Pollak, J. K. (1957). The metabolism of Ascaris lumbricoides ovaries III. The synthesis of alanine from pyruvate and ammonia. Australian Journal of Biological Sciences 10, 465–74.CrossRefGoogle Scholar
Read, C. P. (1966). Nutrition of Intestinal Helminths. In Biology of Parasites, Ed. by Soulsby, E. J. L., pp. 101–26. New York and London: Academic Press.Google Scholar
Rothstein, M. & Tomlinson, G. A. (1961). Biosynthesis of amino acids by the nematode Caenorhabditis briggsae. Biochimica et Biophysica Acta 49, 625–27.CrossRefGoogle ScholarPubMed
Smith, M. H. & Lee, D. L. (1963). Metabolism of haemoglobin and haematin compounds in Ascaris lumbricoides. Proceedings of the Royal Society of London, Ser. B, 157, 234–57.Google Scholar
Stoner, R. D. & Hankes, L. V. (1958). In vitro metabolism of DL-tyrosine-2-C14 and DL-tryptophan-2-C14 by Trichinella spiralis larvae. Experimental Parasitology 7, 145–51.CrossRefGoogle ScholarPubMed
Tobe, S. S. & Loughton, B. G. (1969). An investigation of haemolymph protein economy during the fifth instar of Locusta migratoria migratorioides. Journal of Insect Physiology 15, 1659–72.CrossRefGoogle Scholar
Wyatt, S. S. (1956). Culture in vitro of tissue from the silkworm, Bombyx mori L. Journal of General Physiology 39, 841–53.CrossRefGoogle ScholarPubMed